93 4l60E (probably electrical) Problem with shifting.

[Wozny]

If you do a search for TV cable you might see a description of what that cable does and how adjusting it affects the shifting. If it’s too tight or too loose it will cause either hard late shifts or premature shifts. I think TV stands for throttle valve. It uses the throttle speed to work the valve body. I don’t think the computer is involved. I believe that if there’s a pressure gauge in the cab, the driver can monitor the adjustment of the TV cable by reading the fluid pressure at certain points (ports) at various places around the valve body. I think there is one place in particular that’s just for running a line to a gauge. I was going to add one but decided to put a stick shift 5 speed in. The TV cable is quite important to how it shifts. They can wear out and or get out of adjustment. It goes from the throttle linkage to the valve body.

 

[ODaily]

700R4 / 4L60 yes. But in 93 they went to the 4L60E, with the E standing for Electronic. All computer control, no TV cable used. Thanks for the thought though.

 

[ODaily]

Things I have learned.

Fluid level. I forgot to mention this before, but it's a little overfull. Maybe 1.5 qts. Will fix this. Just don't wanna pop the drain twice if I do have to get into the pan again.

TPS. .517 volts to 4.438 volts. Smooth transition. No spikes, jumps, skips, dead spots, etc.

Running without trans plugged in. P R N perfectly normal. OD takes off very high geared. Assumably in 3rd gear. That's what if feels like. No slippage in trans otherwise. Didn't test D-2-1. Was also very suprised it didn't throw a Check Engine light. It may have thrown a code without the light, I didn't think to check while I was there.

 

[tayto]

sounds like 3rd gear is ok.i think the next sept is verifying if the pcm is seeing the speed signal

 

[ODaily]

I'm getting ready to head to my shop.

I'm thinking I should check the signal on VSS buffer, pin A10, right?
While there, I might check C13 Throttle position sensor? Just to make sure it acutally gets to the ECM?

Will head that way shortly, anything else I might take a look at?

 

[ODaily]

Wait, I think I was looking at a wiring diagram without a trans. Most likely for manual trans.

TP sensor, A15 Dark Blue wire.
Speed sensor, F12 Brown wire.
Shift solenoid A, E9 Light Green wire.
Shift solenoid B, E8 Yellow with Black stripe wire.

Back soon.

 

[ODaily]

TP sensor at ECM .501 vdc

Speed sensor at Ecm with rear axle on jack stands.
0 mph with foot on brake. 5.017 vdc
28 mph 1400 rpm 2.36 vdc
35 mph 1800 rpm 2.26 vdc
40 mph 2000 rpm 2.36 vdc
45 mph 2200 rpm 2.177 vdc
50 mph 2400 rpm 2.139 vdc

Those values aren't exact. I was trying to foot feather the throttle to a specific speed while reading the tach in the dash, and the multimeter in the glovebox.

 

[tayto]

TPS voltage .5 @ idle is fine. i would try and find the pin for the speedo and compare those voltages. again im use to using a scan tool so i dont know if those voltages are good or not. i think with wheels not moving it should be @ 0Vdc, but im not sure. what PCM do you have?

have you removed the valve body at any point?

 

[tayto]

this is from a '7427, but should be the same as what you're running. look at F13

 

[ODaily]

Trans was totally dismantled including valve body for rebuild 1.5 to 2 years ago.
I opened up the pan and pulled the front pump to replace the gasket while leak hunting prior to all this happening. I didn't pull anything unnecessary. The valvebody was untouched.